652 BRITISH FOSSIL REPTILES. 



vifjer ; were this a character of generic value, it might unite T/ieriosuchus with Ilalcrosia, 

 Gray.i 



The alveolar part of the maxillary in which the canines are developed make a 

 corresponding convex extension of its outer border, as in Goniopholis. 



The extent of the 'symphysis mandibulae ' and the angle of divarication of the 

 rami are shown in fig. 4, PI. 44. 



The matrix was removed as far as practicable from the palatal surface of the skull 

 (fig. 4) and exposed a portion of the basisphenoid (.i), of the pterygoids (24), of the 

 palatines (20), and palatal plates of the maxillary (21) ; the pterygo-maxillary vacuities {y) 

 and the hind portion of the palatonares (w) were brought into view. What seems to be 

 a portion of the hind part of a mandibular ramus was so wedged down upon a part of 

 the palatal surface that, in regard to the fragile character of this unique skull, it was 

 deemed unadvisable to attempt its removal. 



In PI. 45 a portion of the skeleton of Theriosuchus prmllus is figured. It is of one 

 individual. In the slab of matrix in which it is imbedded the fore part, marked a, a, is 

 continued on from the hind part with an interval of the extent marked b. At this 

 interval the slab has been broken across, but the parts appear to have been naturally 

 readjusted before the specimen was fixed in its present frame. The position in which 

 the two portions of the skeleton are figured relates to the convenience of size of the 

 Plate. 



'j'he skull has been displaced and fractured, but tlie contiguity of the preserved portion 

 ■with the vertebral column supports the conclusion that it formed part of the skeleton of 

 the same individual. It thus serves to determine the species to which the subject of 

 Plate 45 belonged . 



The part of the skull includes the parieto-mastoid platform (7, 12') with the tympanic 

 (28) and the squamosal (27). The articular surface of the tympanic for the mandible shows 

 the Crocodilian character. The median or sagittal ridge of the parietal is well marked, 

 and is continued along the raid-frontal. This character is partially effaced by mutilation 

 in the more entire skull (PI. 44, fig. 3). It is well shown in the frontal bone indicating 

 the largest of the specimens of Theriosuchus (ib., fig. 8). 



The vertebral centrums of the trunk show the shallow Araphicrolian character of 

 those of the Goniopholis and Teleosaurians. The smooth under or dermal surface of 

 part of the two median rows of the dorsal scutes are shown in the fore half of the 

 skeleton. In the hind half the upper or epidermal surface of the scutes is exposed, 

 showing in most the submedial longitudinal ridge. This is wanting in certain, probably 

 lateral, scutes, of which a group is exposed at the fore part of the anterior portion of the 

 skeleton. One of these unridged, but toothed, scutes is figured at fig. 3, PL 45. 



Of the limb-bones preserved may be recognised the right scapula (,51) and humerus 

 (53), the left humerus (53) with the radius (54) and ulna (55), followed by some dislocated 



1 'Trans. Zool. Soc.,' vol. vi, p. 135. 



